Titanium dioxide is very widely used as an opacifier and colorant in very many applications, including in paper and paper products, in paints, coatings and coated goods, and in thermoplastics, thermosets and the articles made therefrom. A variety of inorganic and organic surface treatments have been developed over the years to provide certain desired attributes to base titanium dioxide pigments whether made by the older sulfate process or the more recent chloride process.
In thermoplastic applications in particular, processors desire pigments which disperse quickly and cleanly in their mixing systems, offer good tinting and opacifying properties, and provide extended run times with a minimal amount of residue. Further, since the manufacture of thermoplastic compositions and of finished thermoplastic goods involves exposing the included pigments to elevated temperatures for often substantial periods of time, it is especially desired that the pigments available for such applications have not only the aforementioned properties but also have excellent thermal stability.